The present invention relates to a device for operating guiding tongues of a product diverter for use, for example in polygraphic machines. The product diverter of this kind is designed for diverting a stream of sheets to be folded, for example, or diverting singular sheets to different paths.
From DE-PS No. 1,044,589 a device for sorting out defective sheets is known wherein a cam disk driven synchronously with a cross cutter moves via a lever system the guiding tongues of the diverter until the movements of the cam disk are inactivated by means of an electromagnetic locking mechanism. This known device, however, enables the sorting of sheets having predetermined fixed characteristics but cannot selectively divide the entire stream of sheets or alternately divert selected sheets from the stream to different directions.
Known are also devices which divide a stream of products or sheets in such a manner that one product is diverted in one direction and the next product is diverted in another direction. For example, DE-AS No. 25 59 138 discloses a diverter for directing flat workpieces from a conveyor belt onto two subsequent conveyor belts. The guiding tongues in this prior art device alternately receive driving impulses through springs activated upon the release of locking pawls or catches tensioned in reciprocating cycles by means of a crank drive of a sliding wedge mechanism which also releases the locking pawls. It is true that devices of this kind are suitable for dividing a stream workpieces. Nevertheless, their main disadvantage is the inability to alternate the division of the stream of the workpieces or to divert at a predetermined time point the entire stream to one or other direction. Another disadvantage of these known devices is a high noise level during operation.
Another device of this kind is known from DE-AS No. 22 29 286 which serves for sorting out defecting pieces in paper processing machines and offers the possibility to divert after a predetermined number of pieces, the path of their transportation. A synchronized locking mechanism cooperates with a pneumatic double-acting locking cylinder controlled by different signals. By means of the working cylinder a pressure accumulator is created for an instantaneous switchover when a gap in the product stream occurs. This mechanism which is advantageous for a synchronized control is also unable to solve the problem of an alternating switchover at a high frequency because the relatively high inertia of the pneumatic drive and the numerous additional control members prevent such fast changes.